K2 Ultracool Dwarfs Survey – VI. White light superflares observed on an L5 dwarf and flare rates of L dwarfs

@article{Paudel2020K2UD,
  title={K2 Ultracool Dwarfs Survey – VI. White light superflares observed on an L5 dwarf and flare rates of L dwarfs},
  author={Rishi R. Paudel and John E. Gizis and Dermott Mullan and Sarah J. Schmidt and A. J. Burgasser and Peter K. G. Williams},
  journal={Monthly Notices of the Royal Astronomical Society},
  year={2020},
  volume={494},
  pages={5751-5760}
}
Kepler K2 long cadence data are used to study white light flares in a sample of 45 L dwarfs. We identified 11 flares on 9 L dwarfs with equivalent durations of (1.3 - 198) hr and total (UV/optical/IR) energies of $\geq$0.9 $\times$ 10$^{32}$ erg. Two superflares with energies of $>$10$^{33}$ erg were detected on an L5 dwarf: this is the coolest object so far on which flares have been identified. The larger superflare on this L5 dwarf has an energy of 4.6$\times$ 10$^{34}$ ergs and an amplitude… 

Figures and Tables from this paper

EvryFlare. III. Temperature Evolution and Habitability Impacts of Dozens of Superflares Observed Simultaneously by Evryscope and TESS
Superflares may provide the dominant source of biologically relevant UV radiation to rocky habitable-zone M-dwarf planets (M-Earths), altering planetary atmospheres and conditions for surface life.
Flares in open clusters with K2
Context. Magnetic fields are a key component in the main sequence evolution of low mass stars. Flares, energetic eruptions on the surfaces of stars, are an unmistakable manifestation of magnetically
On the Correlation between L Dwarf Optical and Infrared Variability and Radio Aurorae
Photometric variability attributed to cloud phenomena is common in L/T transition brown dwarfs. Recent studies show that such variability may also trace aurorae, suggesting that localized magnetic
Radio Emission from Binary Ultracool Dwarf Systems
Well-characterized binary systems will provide valuable opportunities to study the conditions that are necessary for the onset of both auroral and nonauroral magnetospheric radio emission in the
A Unified Spectroscopic and Photometric Model to Infer Surface Inhomogeneity: Application to Luhman 16B
Extremely large telescopes (ELTs) provide an opportunity to observe surface inhomogeneities for ultracool objects including M dwarfs, brown dwarfs (BDs), and gas giant planets via Doppler imaging and

References

SHOWING 1-10 OF 100 REFERENCES
K2 Ultracool Dwarfs Survey. I. Photometry of an L Dwarf Superflare
We report on K2 Campaign 8 measurements of a huge white light flare on the L1 dwarf SDSSp J005406.55-003101.8 (EPIC 220186653). The source is a typical L1 dwarf at a distance of ∼50 pc, probably an
K2 Ultracool Dwarfs Survey. III. White Light Flares Are Ubiquitous in M6-L0 Dwarfs
We report the white light flare rates for 10 ultracool dwarfs using Kepler K2 short-cadence data. Among our sample stars, two have spectral type M6, three are M7, three are M8, and two are L0. Most
K2 Ultracool Dwarfs Survey. II. The White Light Flare Rate of Young Brown Dwarfs
We use Kepler K2 Campaign 4 short-cadence (one-minute) photometry to measure white light flares in the young, moving group brown dwarfs 2MASS J03350208+2342356 (2M0335+23) and 2MASS J03552337+1133437
ASASSN-16ae: A POWERFUL WHITE-LIGHT FLARE ON AN EARLY-L DWARF
We report the discovery and classification of SDSS J053341.43+001434.1 (SDSS0533), an early-L dwarf first discovered during a powerful ΔV < −11 magnitude flare observed as part of the ASAS-SN survey.
EXTraS discovery of an X-ray superflare from an L dwarf
We present the first detection of an X-ray flare from an ultracool dwarf of spectral class L. The event was identified in the EXTraS database of XMM-Newton variable sources, and its optical
KEPLER MONITORING OF AN L DWARF I. THE PHOTOMETRIC PERIOD AND WHITE LIGHT FLARES
We report on the results of 15 months of monitoring the nearby field L1 dwarf WISEP J190648.47+401106.8 (W1906+40) with the Kepler mission. Supporting observations with the Karl G. Jansky Very Large
Kelu-1 Is a Binary L Dwarf: First Brown Dwarf Science from Laser Guide Star Adaptive Optics
We present near-infrared (1-2.4 μm) imaging of the L dwarf Kelu-1 obtained with the Keck sodium laser guide star adaptive optics (LGS AO) system as part of a high angular resolution survey for
A SURVEY FOR Hα EMISSION FROM LATE L DWARFS AND T DWARFS
Recently, studies of brown dwarfs have demonstrated that they possess strong magnetic fields and have the potential to produce radio and optical auroral emissions powered by magnetospheric currents.
A Chandra X-ray detection of the L dwarf binary Kelu-1 - Simultaneous Chandra and Very Large Array observations
Context. Magnetic activity in ultracool dwarfs, as measured in X-rays and Hα, shows a steep decline after spectral type M7-M8. So far, no L dwarf has been detected in X-rays. In contrast, L dwarfs
Dwarfs Cooler than “M”: The Definition of Spectral Type “L” Using Discoveries from the 2-Micron All-Sky Survey (2MASS)
Before the 2-Micron All-Sky Survey (2MASS) began, only six objects were known with spectral types later than M9.5 V. In the first 371 deg2 of actual 2MASS survey data, we have identified another 20
...
...